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Topic: Fresh yeast (Read 9911 times)

I've seen many posts that speculate or conclude fresh yeast (CY) produces a different (read: better) finished product than does ADY or IDY (assuming proper conversion). I'm curious if you've found this to be true in your experience, and if so, why? They are all the same organism, aren't they?

Craig

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"We make great pizza, with sourdough when we can, commercial yeast when we must, but always great pizza."Craig's Neapolitan Garage

The fresh yeast I bought from a local bakery smelled so bad,I ended up throwing out a dough I made with it.My gawd,did it stink!

I still want to try another type of fresh yeast again,but the one I used,the gross sweaty feet/socks,sour beer smell was too much for me to deal with.Where I live,there is not much selection to buy from someone else.

Just as a note, Tom has made his opinion/test outcomes known on this subject before. His conclusion was that results are all equal assuming all forms of yeast are used as directed and at the right rate. Personally, I favor cake yeast for both flavor and spring. The thing that really gets me is the smell of the dough after making it. I can never really detect the smell of IDY or ADY in a freshly made dough. I can detect it in a dough made with fresh yeast, easily. Add a long fermentaion to that and it makes me wonder if the tests Tom and the AIB have done are less conclusive due to using a yeast rate favored to production, rather than flavor and texture development. In my eyes, for the AIB, there are two ways to make bread. One is with a starter, aiming for maximum flavor and texture, the other is with yeast, mainly for mass production, and while the aim is to produce an excellent loaf, the goal is still to do it as efficiently as possible. I think some of us are using yeast differently than they may have been used in the AIB tests some time ago. Just my thoughts. -Marc

I agree with Marc. The flavor and texture that fresh yeast brings is palpable. There is a reason that many bakeries and pizzerias use it - otherwise the much less perishable IDY would be their choice for obvious reasons.

I agree with Bill. The flavor and texture that fresh yeast brings is palpable.

I've heard this said enough times to start to believe it. What I'm trying to understand is why this would be the case if the amount used is properly converted between forms. Why would a different delivery vehicle for the same organism yield a different flavor?

Craig

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"We make great pizza, with sourdough when we can, commercial yeast when we must, but always great pizza."Craig's Neapolitan Garage

I've heard this said enough times to start to believe it. What I'm trying to understand is why this would be the case if the amount used is properly converted between forms. Why would a different delivery vehicle for the same organism yield a different flavor?

Craig

Not sure. There may be some connection with the state of the yeast, not having gone through the drying process to the extent of ADY and IDY. And it may be the placebo effect, who knows - irregardless I enjoy working with CY more than the others.

Craig;The end result from using fresh compressed yeast and IDY are exactly the same, no difference. ADY, due to the presence of damaged yeast cells provides a little softening to the dough, but nothing else to the finished bread. A number of years ago we did a seamless transition to IDY in our Experimental Bakery where we used it exclusively for several years, and then ultimately transitioning back to using compressed yeast (a political move) just as seamlessly.Tom Lehmann/The Dough Doctor

parallei

I've no opinion on this issue as the last time I used CY was to try and make some apricot wine at the age of 12 (science experiment!). However, this is what the San Francisco Baking Institute has to say:

I've no opinion on this issue as the last time I used CY was to try and make some apricot wine at the age of 12 (science experiment!). However, this is what the San Francisco Baking Institute has to say:

The second sentence sums it all up for me: "One baker even told us that when he switched from dry yeast to fresh yeast, the flavor of his bread improved. We would like to dispel the myth..."

Was this baker lying? According to SFBI he was delusional because in their opinion fresh yeast is the same as IDY/ADY. There are those who say DOP San Marzanos are the same as US grown plum tomatoes - no difference in taste. Some people even say powdered garlic tastes the same as fresh. I say make your own judgement, because your experience may be different from what people are telling you.

Jackie;IDY and CY (compressed yeast) are closer together than CY and ADY. While IDY also has its share of damaged yeast cells due to the drying process, the issue has been addressed through the addition of a small amount of ascorbic acid to the dry yeast, while the ADY (active dry yeast) has not had any ascorbic acid added, so the doughs made with ADY actually end up slightly softer than when made with IDY. The biggest problem that we have seen is with conversion of one type of yeast to another. When used at correct conversion levels, there is no difference in finished product flavor between IDY, ADY, or CY. The trick here is in using the CORRECT conversion, and the conversion recommended by the manufacturer, may not always be the correct one for your particular dough formula. For bread makers, the correct conversion level is the one that provides the same final proof time as the yeast type being replaced. For pizza makers, I like to use a plastic glass or cup, oil the inside and place a weighed amount of dough into the cup/glass, flatten the top so it is as even as possible, lightly cover with a piece of foil and set aside to proof/rise until the dough reaches the top edge of the glass/cup, then record the time required for the dough to rise to that height, now, replace the yeast with the type you want to use, and repeat, adjust the yeast level until the time needed for the dough to rise to the top edge is the same as with your original yeast. Now, divide the new yeast level by the original yeast level and you will have the correct conversion for your specific dough.Tom Lehmann/The Dough Doctor

The second sentence sums it all up for me: "One baker even told us that when he switched from dry yeast to fresh yeast, the flavor of his bread improved. We would like to dispel the myth..."

Was this baker lying? According to SFBI he was delusional because in their opinion fresh yeast is the same as IDY/ADY. There are those who say DOP San Marzanos are the same as US grown plum tomatoes - no difference in taste. Some people even say powdered garlic tastes the same as fresh. I say make your own judgement, because your experience may be different from what people are telling you.

I don't think it is likely that he is lying or delusional, but that does not mean there was a flavor difference either. It is the idea that perception is reality. I saw examples of this dozens, if not 100's of times when I was in the food manufacturing business. You can give people two samples of the exact same product (from the exact same batch even), and if they have any reason to think they are different, they will often pick one that they like better. If they have a reason to think they will like one better, they almost certainly will. I have had people swear up one side and down the other that something was much better than something else that was actually the exact same thing.

CL

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"We make great pizza, with sourdough when we can, commercial yeast when we must, but always great pizza."Craig's Neapolitan Garage

scott123

FWIW, the few times that I used cake yeast, purchase in a lb. block from a bakery with good turnover (not from the supermarket aisle), I seemed to get better oven spring than from using idy or ady. And it wasn't just a quantity thing either- I couldn't just add more IDY to match the results of the cake.

Now that is interesting. The article states that different strains of S. cerevisiae are used to make the different types of yeast. I've never seen that in print before. Have you seen this written any place else?

Although this article has been referenced many times here on the forum, I find it interesting that as a living organism, yeast is cultivated, rather than manufactured. It is even mentioned that a carbohydrate food source such as molasses is required for reproductive yeast growth. http://www.theartisan.net/The_Artisan_Yeast_Treatise_Section_One.htm

I donít know why, but I also prefer cake yeast in doughs, when I can find it. To me Red Star cake yeast smells like sourdough when added to water. Maybe my smeller is off.

Norma, I am sure there are members who will disagree with me, but you can propagate that CY in a starter like form. This way you can have access to the same organisms whenever you need them. I have been doing this for awhile now with seemingly consistent results. All you have to do is to make a 50/50 mixture of flour and water and then add your CY. Maintain it like you would a starter and the same yeast organisms should just replicate themselves. By doing this, you don't have to keep buying fresh yeast.

That or divide the block into multiple pieces, double wrap, vacuum seal, and freeze. CY will last for a very long time in the freezer.

Norma, I am sure there are members who will disagree with me, but you can propagate that CY in a starter like form. This way you can have access to the same organisms whenever you need them. I have been doing this for awhile now with seemingly consistent results. All you have to do is to make a 50/50 mixture of flour and water and then add your CY. Maintain it like you would a starter and the same yeast organisms should just replicate themselves. By doing this, you don't have to keep buying fresh yeast.

That or divide the block into multiple pieces, double wrap, vacuum seal, and freeze. CY will last for a very long time in the freezer.

Chau

Chau,

I am always interested in your experiments or what you think. I didnít know that CY can be propagated in a starter like form. I never remembered you posting about that. I would like to have access to the same organisms whenever I want to use them. I will start an experiment using your methods and see what happens. It would be great if I didnít have to buy CY because most of the time I canít find it in my area. I wonder if since some yeasts are fed molasses when they are started if molasses could be added to help propagate the yeast better.

I do have some frozen cake yeast I have been recently using, but wonder how long it will last frozen.

Now that is interesting. The article states that different strains of S. cerevisiae are used to make the different types of yeast. I've never seen that in print before. Have you seen this written any place else?

I have researched and written on this subject (at a fairly elementary level) several times over the last several years. In fact, when I did an Advanced forum search this morning using my forum name and the terms yeast and strain, I got a bit over a page of hits. A lot of what I have written is repetitive, as the same questions on yeast would pop up from time to time. But I first became aware of the strain issue several years ago after reading an article, possibly one by Tom Lehmann, that said that IDY and ADY were different strains (and with different particle geometry also). And then there was a period where I had several exchanges by email and telephone with yeast producer like Fleischmann's and Red Star/SAF where I tried to find out whether the retail brands of their yeast products sold to mostly home bakers (like the Rapid Rise and similar fast-rise yeast products) were identical to those sold to professional bakers, which many of our members were using in the one- and two-pound bags. Getting answers to these simple questions was like pulling teeth and, to this day I am not absolutely certain, but the impression I came away with is that the yeast strains of the retail yeast products were not identical to those at the professional baker level but that any performance differences were minor and of no concern.

As an aside, from my experience dealing with yeast producers, I came to the conclusion that it is best to try to speak with someone on the foodservice side of the business where you are far more likely to be able to speak with a technical person familiar with the technical aspects of their yeast products. On the retail side, you get people who are more used to dealing with home consumers with the most basic of questions.

I think a good article to read on this subject, as well as other related topics, is the one at http://www.pizzamaking.com/forum/index.php/topic,8912.0.html. What I found interesting is the statement at the end of the article where it says that it can take up to ten years to develop a new yeast from strain to commercial product.

Aren't there more dead cells per gram of fresh yeast than for the pelletized versions? Performance aside, could this be adding a perceptible flavor that the pelletized form doesn't have?

Dan,

To the best of my knowledge, fresh yeast is about 70% water and all of the cells are live cells. See, for example, the quoted material in Reply 8 at http://www.pizzamaking.com/forum/index.php/topic,14060.msg141140/topicseen.html#msg141140. It is possible to destroy some of such cells by freezing the yeast, and especially if the freezing is done slowly, as in a static freezer, and in such a case one can expect the release of glutathione, which is an amino acid component of the dead cells. Otherwise, with the recommended use of the fresh yeast one should get good gassing power.

I have heard of using large amounts of dry yeast to get more crust flavor, in most cases because many professionals have gone to dry forms of yeast, but I recall that according to Professor Raymond Calvel in his book The Taste of Bread, you need at least 2.5% fresh yeast to taste it in a finished bread. He did not give a corresponding percent for ADY or IDY.

but I recall that according to Professor Raymond Calvel in his book The Taste of Bread, you need at least 2.5% fresh yeast to taste it in a finished bread. He did not give a corresponding percent for ADY or IDY.